Binding of Imidazoles and Pyridines to the Atropisomers of Zinc Tetra(ο-pivalamidophenyl)porhyrin

• ANZAI KAZUNORI

  Faculty of Pharmaceutical Sciences, Nagoya City University

• HOSOKAWA TAKASHI

  Faculty of Pharmaceutical Sciences, Nagoya City University

• HATANO KEIICHIRO

  Faculty of Pharmaceutical Sciences, Nagoya City University

Abstract

Complex formation of four atropisomers of zinc tetra(ο-pivalamidophenyl)porphyrin with imidazoles (imidazole, 1-methylimidazole, 2-methylimidazole, and benzimidazole) and pyridines (pyridine, 3,5-dimethylpyridine, and 2,6-dimethylpyridine) was studied. The ratios of the absorbance of the βband to the αband in the adducts tended to be in the order of αααα>ααββ≧αααβ>αβαβ. This order, which is the same as that of "electronic effect" on the physical properties of the four atropisomers of tetra(ο-pivalamidophenyl)porphyrin, indicates the presence of "electronic effect" in the zinc derivatives of the porphyrin. Among the four isomers, the equilibrium constants of N-base binding tended to be in the order of αβαβ>αααα≧αααβ>ααββ, suggesting the relatively greater importance of "steric effect" of the bulky pivalamido groups rather than "electronic effect" for the coordination of the N-bases. The differences in the equilibrium constants among the atropisomers are attributable to the contributions of both the steric effect and the electronic effect.

Journal

• Chemical & pharmaceutical bulletin

  Chemical & pharmaceutical bulletin 34 (5), 1865-1870, 1986-05-25

  The Pharmaceutical Society of Japan

Keywords

• atropisomer
• picket-fence porphyrin
• zinc tetra(ο-pivolamidophenyl)porphyrin;imidazole
• pyridine
• axial coordination equilibrium
• steric effect
• electronic effect

Details

• CRID: 1572824502322329728
• NII Article ID: 110003626318
• NII Book ID: AA00602100
• ISSN: 00092363
• Text Lang: en
• Data Source:
  • CiNii Articles